Film-forming epoxy-functional vinyl polymers in the form of styrene-glycidyl methacrylate copolymers (styrene:glycidyl methacrylate weight ratio=85:15) are known in the art. These copolymers form hard, insoluble films when mixed with methyl isobutyl ketone, then combined with phosphoric acid at the rate of 0.85 mol phosphoric acid per 1 mol epoxy group, and heated for 30 minutes at 150.degree. C. These films are reported to exhibit a hardness and weatherability superior to those of alkyd nitrocellulose films (The Preparation and Applications of Epoxy Resins, published by Kobunshi Kagaku Kanko-kai Kabushiki Kaisha, 1963, pp. 113-115).
Silicone-type epoxy-functional vinyl polymers are also known in the form of copolymers obtained by the graft polymerization of glycidyl methacrylate and acrylate ester with the cocondensate of gamma-methacryloxypropylmethyldimethoxysilane and cyclic dimethylsiloxane, as disclosed in Japanese Patent Application Laid Open Number Hei 2-138360.
However, since the epoxy group in these prior-art epoxy-functional vinyl polymers is the glycidoxy group, they suffer from the particular problem of a low ring-opening and crosslinking reactivity under the action of electrophilic reagents such as, for example, acids. Moreover, it is difficult to obtain highly releasing and highly water-repellent films from these epoxy-functional vinyl polymers even when they can be cured. Thus, demand exists for a silicone-grafted vinyl polymer that would contain the highly reactive alicyclic epoxy group.